Wash rice and soak in water for 30 minutes.

Wash Urad dal and soak in water separately for 30 minutes.

Drain the rice and grind to make a fine batter by adding little water at a time to make a thick and smooth batter.

Similarly, drain the dal and grind to make a smooth batter with as little water as possible to get a smooth batter.

In a large mixing bowl, combine both the rice and the urad dal batter. Whisk in the curds, the red chili paste, asafoetida, and salt.

Let the batter rest for 30 minutes to one hour.

Heat the Appachatti and grease it uniformly with oil.

Pour a ladle of batter into the center of the pan. Hold the pan with both the handles and quickly swirl it around so that the batter coats base and sides of pan evenly. Drizzle few drops of oil.

Cover pan and cook over low heat till the middle of the dosa is cooked and the edges browned.

Once done, remove the Thavalai Dosai with a spatula and serve.